This invention relates to a new and improved apparatus and process for producing non-linear exit cones, rocket motors, and similar components for rockets, and the like. If a rocket can be made having a lighter exit cone of good structural integrity, it will consume less fuel, have a longer range, and a launch can be made more quickly and easily, with reduced possibility of detection.
Heretofore, it has not been possible to uniformly wrap a continuous length of fabric such as graphite on non-linear wrapping forms having the shape of, say, an exit cone. Hence, the present fabrication of these types of rocket exit cones usually involves applying rosette sections of graphite cloth to a mandrel, or winding a filament on a mandrel. This is followed by impregnating with resin, and the curing and shaping to its ultimate configuration. These exit cones have non uniform and inadequate structures that lead to frequent catastrophic failures when firing on the pad, or after launch.
To a certain extent, the problem can be compensated by building an exit cone having a thick wall for the conical portion. However, since the conical portion is the heaviest part of the exit cone, this adds considerable weight to the system. Consequently either the range of the rocket is limited, or more fuel is required for launching, thereby imposing restrictions on the rocket design. Also, a heavy exit cone makes it difficult to site and handle the rocket prior to launch, and transporting the device also is difficult.
It would be preferred to produce an exit cone having a conical wall thickness of about 1/4 inch, or greater, while improving its tensile properties and structural characteristics. Moreover, if the usual conical wall thickness could be reduced by machining down to this 1/4 inch thickness, the weight of the exit cone could be reduced greatly, and this would be extremely useful, particularly if the structural integrity and weight and requirements were improved. A desirable process would produce exit cones of up to about 6 feet in diameter, and up to about 8 feet long.
Also, it would be desireable to produce a uniform transition between the cylinder portion and the conical protion and at the same time conform the junction between the conical and cylinder portions to a desired shape.
A process fo producing an exit cone preferably should be continuous so that important process conditions can be controlled while wrapping the fabric. These process conditions include wrapping seeds, fabric tension, fabric feed rates, traverse times, rates and distance traversed by the wind up form, etc.
In addition, a process for producing an exit cone is desired that would give a fabricator the option of whether or not pressure is applied to the wrapped fabric prior to the resin cure stage.